New
#1
Sauerbraten
I have played this game for around a year now - The new edition (Justice) was released earlier this year and is well worth the look if you are into free fps multiplayer games.
The insta mode is rifle only + one shot one kill
You then have ffa etc which has a host of weapons in quake style play. (I personally don't really like this mode.
Cube 2: Sauerbraten Windows/Linux/mac